Children's social adjustment is a significant predictor of their later mental health. The aim of this project is to study the early development of interpersonal processes by analyzing how children's social behaviors and relationships evolve over the course of a year and develop during the preschool years. Despite the importance of this period in the development of children's social skills, there have been few in-depth studies of the specific changes that occur during this time. The basic hypothesis of this study is that, as children grow familiar with each other, their relationships become more reciprocal, stable and exclusive, and their expectations of each other become more established. As reputational factors and past history become more salient in children's responses to each other, popular children become increasingly successful in initiating and maintaining peer contacts, while unpopular children become less successful. Furthermore, as peer relationships develop, interactions between frequent friends become longer and more complex than contacts between casual acquaintances. In this study, 83 children from ages three to six are being observed and interviewed over the course of a year. Children's social behaviors and contact patterns will be recorded with event samples, spot observations and videotaped time samples. Interviews include sociometric tasks and hypothetical social-problem-solving situations. The data will be collected by May of 1987; funding is being requested to support the analysis of the data and to prepare the study for publication. The long-term objectives of this project are the design of more effective means to identify and treat children at risk for poor social adjustment.